Stakes in outsourcer Capita and online estate agency Purplebricks have been the main factors behind this year’s poor performance.

The value of Woodford's 11 per cent stake in struggling outsourcer Capita has plummeted in recent weeks following a collapse in its share price, while his stake in Purblebricks has also fallen in value after Jefferies analysts claimed the firm had hidden the true number of homes it was selling.

A spokesperson for Woodford said: “Neil has to make decisions about the allocation of capital all the time.

“When we sell, or don’t participate in a funding round, it is not a function of an inability to follow on, but typically a function of our preference to focus our capital on businesses earlier in their lifecycle or which have the potential for more attractive returns.”